print('Wellcome to Python Pizza Delivery')

size = input('What size Pizza do you want? S, M or L ')
add_pepperoni = input('Do you want pepperoni? Y or N ')
extra_cheese = input('Do you want extra cheese? Y or N ')

currency = "$"
small = 15
medium = 20
large = 25

pepperoni = [2, 3]
cheese = 1

bill = 0

if size == "S":
    bill += small
elif size == "M":
    bill += medium
else:
    bill += large

if add_pepperoni == "Y":
    if size == "S":
        bill += pepperoni[0]
    else:
        bill += pepperoni[1]

if extra_cheese == "Y":
    bill += cheese

print(f"Your final bill is: {bill}")